This contribution gives an overview of the use, therapeutic effects and side effects of the antibiotic substance Metronidazole. Metronidazole is effective in the treatment support of paradontitis, microbial-caused halitosis, perioral skin infections and odontogenic hard or soft tissue abscess formations related to anaerobic bacterial infections. Due to its anti- parasitic effect, Metronidazole is also effective in the treatment of protozoa. In adults and children from 12 years on, 200 mg Metronidazole to a maximum of 2000 mg Metronidazole per day can be administered. In children below 12 years of age, an antibiotic dose of Metronidazole between 20 to 30 mg per kilogram body weight is advised.